we've got these two suspicious letters addressed to president obama and republican senator roger wicker and law enforcement sources say they have a person of interest, so we expect the investigation is moving forward. it's important to note both of these letters were stopped at offsite facilities, so they did not get close to the white house or the united states capitol. at the white house, jay carney says the president's been briefed and offered this update. >> the f.b.i. has a lead for determining whether a suspicious powder is a dangerous substance such as risin. and those take place at accredited facilities and they take a certain amount of time, as the f.b.i. has indicated. these procedures are in place. the procedures are effective and in operation now and we are in the midst of that process, which the f.b.i. is your taking at this time -- undertaking at this time. >> heightened security has brought heightened security activity on capitol hill, suspicious package was delivered to the office of alabama republican senator richard shelby. it was cleared. the bomb squad was sent to th